#ifndef TIMER_H_
#define TIMER_H_

#include <functional>
#include <chrono>
#include <thread>
#include <atomic>
#include <memory>
#include <mutex>
#include <condition_variable>

class Timer
{
public:
    Timer(): expired_(true)
      , try_to_expire_(false)
    {}


    Timer(const Timer &t)
    {
        expired_ = t.expired_.load();
        try_to_expire_ = t.try_to_expire_.load();
    }

    ~Timer()
    {
        Expire();
    }

    void StartTimer(int interval, std::function<void()> task)
    {
        if (expired_ == false) {
            return;
        }

        expired_ = false;
        std::thread([this, interval, task]() {
            while (!try_to_expire_) {
                std::this_thread::sleep_for(std::chrono::milliseconds(interval));
                task();
            }

            {
                std::lock_guard<std::mutex> locker(mutex_);
                expired_ = true;
                expired_cond_.notify_one();
            }
        }).detach();

    }

    void Expire()
    {
        if (expired_) {
            return;
        }

        if (try_to_expire_) {
            return;
        }

        try_to_expire_ = true;
        {
            std::unique_lock<std::mutex> locker(mutex_);
            expired_cond_.wait(locker, [this]{return expired_ == true;});
            if (expired_ == true) {
                try_to_expire_ = false;
            }
        }
    }

    template<typename callable, class... arguments>
    void SyncWait(int after, callable&& f, arguments&&... args)
    {
        std::function<typename std::result_of<callable(arguments...)>::type()> task
                (std::bind(std::forward<callable>(f), std::forward<arguments>(args)...));
        std::this_thread::sleep_for(std::chrono::milliseconds(after));
        task();
    }

    template<typename callable, class... arguments>
    void AsyncWait(int after, callable&& f, arguments&&... args)
    {
        std::function<typename std::result_of<callable(arguments...)>::type()> task
                (std::bind(std::forward<callable>(f), std::forward<arguments>(args)...));

        std::thread([after, task]() {
            std::this_thread::sleep_for(std::chrono::milliseconds(after));
            task();
        }).detach();
    }

private:
    std::atomic<bool> expired_;
    std::atomic<bool> try_to_expire_;
    std::mutex mutex_;
    std::condition_variable expired_cond_;
};

#endif // TIMER_H_
